Q&A: What you need to know about AFM

The mysterious disease, acute flaccid myelitis, has parents talking — should you be worried?

A neurologic disease, acute flaccid myelitis, has grabbed headlines across the country because not much is known about the serious disorder that strikes children. Dr. Jan B. Wollack of Children’s Hospital at Dartmouth-Hitchcock answered questions about AFM — what it is, the symptoms, and what to do if your child is presenting with those symptoms and more — in November 2018 for readers of ParentingNH.

Question: Parents have been hearing a lot about acute flaccid myelitis (AFM) in the news lately. What exactly is acute flaccid myelitis and why is it garnering so much attention now?

Answer: AFM is a polio-like neurologic disease characterized by weakness in one or more limbs. It is frequently preceded by a febrile (fever) or respiratory illness. In addition to weakness, there is loss of muscle tone and deep tendon reflexes in the affected limb(s). There may also be facial weakness, difficulties swallowing, difficulties speaking and limitation of eye movements.

It first came to attention in 2012 with the report of a number of cases in California, although probably occurred before then. Further attention was drawn to it following a series of cases in Colorado in 2014, at the time of a national outbreak of respiratory illness associated with enterovirus D68. Eventually 120 confirmed cases were reported from 34 different states that year. After that outbreak, the CDC (Centers for Disease Control and Prevention) began a program to monitor it. The number of confirmed cases was only 22 in 2015, but then in 2016 there were 149 cases seen, spread over 39 states. After only 33 cases in 2017, we now seem to be in another year of increased activity, with 80 cases so far, involving 25 states. This increase in activity, along with the intense efforts of the CDC to collect data on these cases in the hopes of finding better treatment, have brought the increased attention.

Q: Do we know what causes AFM?

A: AFM is caused by inflammation of part of the spinal cord. According to the CDC, the cause of this inflammation remains unknown. Possible causes include the direct effect of viruses, or a “parainfectious” inflammation of the spinal cord in response to a virus. The virus most suspected is enterovirus D68, but enterovirus 70, enterovirus 71 and West Nile Virus have also been occasionally found. There are also many cases where no virus can be identified. The exact cause of AFM remains a subject of ongoing investigation.

Q: Who is must susceptible to developing AFM? Can adults get it?

A: Most cases occur in children, but young adults can occasionally get it as well. In one study, 15 percent of the patients were over 21.

Q: What are the symptoms of AFM?

A: As stated, AFM is a polio-like neurologic disease characterized by weakness in one or more limbs. It is frequently preceded by a febrile (fever) or respiratory illness. In addition to weakness, there is loss of muscle tone and deep tendon reflexes in the affected limb(s). There may also be facial weakness, difficulties swallowing, difficulties speaking and limitation of eye movements. Imaging with MRI reveals inflammation in the gray matter region of the spine near the affected limb(s). If a spinal tap is done, inflammatory cells are usually found in the cerebrospinal fluid.

Q: If a child is showing these symptoms, what should a parent do? Can they wait to see a doctor or should they take their child to the emergency room?

A: The faster the medical evaluation, the better, so most of the time going to the emergency room is the best option. AFM is not the only cause of sudden onset of limb weakness. Stroke and Guillain-Barre syndrome are other important causes, which need to be investigated and that may need emergency intervention. The ER is usually the place where MRI and other investigations can be done fastest.

Q: How is AFM treated?

A: Given that the exact cause of AFM is yet to be determined, there is no specific therapy for AFM, and management is therefore “supportive,” i.e., directed at minimizing symptoms. Attempts at using either antiviral agents, or drugs to treat the inflammation in the spine, such as steroids, intravenous immunoglobulin (IVIG) or plasma exchange have shown no evidence of effectiveness. For the longer term, physical and occupational therapy can help the patient to regain strength.

Q: Have there been any cases of AFM diagnosed in New Hampshire?

A: Since 2014, there have only been four confirmed cases in New Hampshire. There is only one suspected (not yet confirmed) case so far this year.

Q: How concerned should New Hampshire parents be about AFM?

A: AFM is very rare. Between August 2014 and October 2018, only 404 confirmed cases were found in the United States. The CDC estimates that it only affects one person in a million. So while it is a serious condition, the odds of getting it are quite small.

Q: Is there anything a parent can do to prevent their child from contracting AFM?

A: General health hygiene can help. Washing one’s hands, or using hand sanitizer, can help prevent catching viruses. Since West Nile Virus can occasionally cause this disorder, the CDC recommends protecting again mosquito bites. They also recommend staying up to date with your vaccinations; while poliovirus has been eliminated from this country, it was the original cause of acute myelitis and can still be found in some parts of the world.

Jan B. Wollack, MD, PhD, is Section Chief, Division of Pediatric Neurology at Children’s Hospital at Dartmouth-Hitchcock and Associate Professor of Neurology at the Geisel School of Medicine at Dartmouth. Melanie Hitchcock is the Editor of ParentingNH and has been a journalist for almost 20 years.